Wipes having a substrate with a discontinuous pattern of a high internal phase inverse emulsion disposed thereon and process of making

ABSTRACT

A wipe comprising a high internal phase inverse emulsion disposed in a discontinuous pattern on a substrate. The pattern provides areas coated with the emulsion and areas free of the emulsion. Preferably the emulsion is disposed so that the surface area to volume ratio of the emulsion is minimized. The emulsion locally expresses water during use upon the application of pressure to the wipe. The water is useful for cleaning. The discontinuous pattern of the emulsion provides regions of the substrate which are wetted during use and regions which may remain dry. The wetted regions transfer water to the surface to be cleaned. The dry regions then remove the water from the surface for more efficacious cleaning.

This is a continuation of application Ser. No. 08/909,449 filed on Aug.11, 1997, now U.S. Pat. No. 5,914,177.

FIELD OF THE INVENTION

The present invention is related to cleaning articles, particularlywipes having a high internal phase inverse emulsion disposed on asubstrate.

BACKGROUND OF THE INVENTION

Substrates having lotions and other coatings are well known in the art.Lotions are often in conjunction with substrates to soften thesubstrate. Lotions can also be used to soothe the skin when thesubstrate is used, for example, as a facial tissue. Examples ofsubstrates having lotion and useful in the facial tissue art are foundin U.S. Pat. No. 4,426,418, issued Jan. 17, 1984 to Coleman et al. andcommonly assigned U.S. Pat. No. 4,481,243, issued Nov. 6, 1984 to Allen,the disclosure of which Allen patent is incorporated herein byreference.

However, these attempts in the art do not solve the problem of how touse the lotion to improve cleaning of the skin with the tissue. Nor dothese attempts show how to clean other surfaces using a substratetreated with a lotion.

Products, such as wipes, have been developed. Certain wipes have asignificant advantage over earlier prior art cleaning products forremoving soiling, particularly from the perianal region. Such wipescomprise a substrate (e.g., a nonwoven or tissue) treated with awater-in-lipid emulsion. Such wipes are particularly advantageous forcleaning, especially when provided in the form of wet-like cleansingwipes used to remove perianal soils. Examples of such wipes and theirmanufacture are found in commonly assigned World Patent Applications WO96/14835, published May 23, 1996, in the names of Mackey et al.; and WO96/21505, published July 18, 1996, in the name of DesMarais, thedisclosures of which are incorporated herein by reference. These wipesrelease significant quantities of water during use for comfortable, moreeffective cleaning.

The lipid phase of the emulsion found in these wipes is sufficientlybrittle so as to be easily disrupted by low shear contact or compression(e.g., during the wiping of the skin) to readily release this internalwater phase, but sufficiently tough at elevated temperatures where thelipid is melted to avoid premature release of the water phase during therigors of processing. The continuous lipid phase of these articles isalso sufficiently stable during storage so as to prevent significantevaporation of the internal water phase. The normal tensile strength andflushability properties of these articles are not adversely affectedwhen treated with the high internal phase inverse emulsions of thepresent invention. As a result, users of these articles get comfortable,efficient, moist cleaning without having to change their normal cleaninghabits. This technology is readily useful for other purposes, such ascleaning hard surfaces, etc.

The cleaning process becomes easier if the emulsion is directly exposedto the surface to be cleaned. Such a wipe may comprise a substratehaving one or two exposed, outwardly facing surfaces, and the emulsiondisposed on one of the exposed surfaces. However, such an embodimentprovides the disadvantages of imparting a tacky feel to the user,potential loss of emulsion from the surface, and difficulties inprocessing. In a preferred embodiment, the emulsion is disposed betweentwo plies of the substrate to yield a laminate.

It has unexpectedly been found that a continuous coating of the emulsionon the substrate does not provide the most efficacious cleaning,particularly when it is desired to clean human skin. A discontinuouspattern of the emulsion on the substrate provides a cleaning mechanismnot found in the prior art. As used herein, a discontinuous pattern ofthe emulsion is a pattern having regions of the substrate free of theemulsion intermediate regions of the substrate upon which the emulsionis disposed.

During cleaning, water is released from the emulsion to remove dirt fromthe skin. The area of the skin wetted by the water and from which dirtis removed is then wiped dry with the regions of the substrate free ofthe emulsion. Similar benefits occur when the wipe is used to cleanother surfaces, such as window glass, countertops, sinks, porcelain andmetal fixtures, walls and the like, and from other surfaces, such ascarpeting or furniture.

The mechanism to transfer the water from the emulsion to the surface tobe cleaned involves several steps. First, the water is released orexpressed from the emulsion due to pressure imparted by the user. Thepressure ruptures the emulsion, freeing the water. The water thensaturates the substrate. Upon saturation, the water penetrates thesubstrate in the Z-direction. Excess water, which is that water inexcess of the local absorbent capacity of the substrate then istransferred from the wipe to the surface.

One potential approach to the problem of providing sufficient quantitiesof water to saturate the substrate and transfer the water to the surfaceis to dispose a continuous layer of emulsion on the substrate. Acontinuous layer of emulsion may contain a greater quantity of waterthan a discontinuous layer of the emulsion. This potential approach hasseveral drawbacks. First, a thin continuous layer of emulsion may notexceed the local capacity of the substrate. Second, excessive lipidphase in the emulsion causes a build up and may not be well received bythe user and contribute to manufacturing difficulties. Third, if theamount of the emulsion becomes too great, it can be difficult to rupturethe emulsion and release the water therefrom. Such difficulty occurs dueto a greater quantity of the lipid phase being present. As the amount oflipid phase increases, slippage of the emulsion relative to itselfoccurs, rather than rupture of the emulsion. Fourth, the surface area tovolume ratio is far from optimal. Finally, the cost of the wipeincreases directly with the amount of emulsion provided.

Accordingly, it is an object of the present invention to provide a wipecomprising a substrate and a high internal phase inverse emulsion. It isfurther an object of the present invention to provide such a wipe havinga discontinuous coating of the emulsion on the substrate. It is finallyan object of the present invention to provide a wipe having such anemulsion disposed in a pattern that provides improved transmission ofwater released from the emulsion to the surface desired to be cleaned,while at the same time minimizing loss of such water from the emulsiondue to evaporation.

SUMMARY OF THE INVENTION

The invention comprises a wipe. The wipe comprises a substrate and ahigh internal phase inverse emulsion disposed thereon. The emulsion isdisposed in a discontinuous pattern so that the substrate has firstregions coated with the emulsion and second regions free of theemulsion.

In a preferred embodiment, the substrate comprises high and low basisweight regions. The emulsion is juxtaposed with the low basis weightregions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of a wipe according to the present inventionshowing two roll positions.

FIG. 2 is a top plan view of an alternative embodiment according to thepresent invention comprising macropatterns of emulsion definingdecorative indicia.

FIG. 3 is a top plan view of an alternative embodiment according to thepresent invention showing a pattern wherein the stripes are defined bydiscrete juxtaposed spheres of emulsion.

DETAILED DESCRIPTION OF THE INVENTION

The wipe disclosed herein may be used for several purposes. For example,the wipe may be used as a facial tissue, bath tissue, paper towel, ababy wipe, an adult wipe, a hard surface cleaner, etc. The intended useof the wipe does not limit the final product.

The Substrate

Referring to FIG. 1, the wipe 8 comprises a substrate 10 and an emulsion12 disposed thereon. The substrate 10 may be cellulosic, particularly atissue, a nonwoven, a foam, or any combination thereof. Suitablecellulosic substrates 10 are described in U.S. Pat. No. 5,245,025,issued Sep. 14, 1993 to Trokhan et al.; U.S. Pat. No. 5,503,715, issuedApr. 2, 1996 to Trokhan et al.; U.S. Pat. No. 5,534,326, issued Jul. 9,1996 to Trokhan et al.; U.S. Pat. No. 4,637,859 issued Jan. 20, 1987 toTrokhan; U.S. Pat. No. 4,514,345, issued Apr. 30, 1985 to Johnson etal.; U.S. Pat. No. 4,529,480, issued Jul. 16, 1985 to Trokhan; U.S. Pat.No. 5,328,565, issued Jul. 12, 1994 to Rasch et al.; U.S. Pat. No.4,191,609, issued Mar. 4, 1980 to Trokhan; U.S. Pat. No. 4,300,981,issued Nov. 17, 1981 to Carstens; U.S. Pat. No. 4,513,051, issued Apr.23, 1985 to Lavash; U.S. Pat. No. 4,637,859, issued Jan. 20, 1987 toTrokhan; U.S. Pat. No. 5,143,776, issued Sep. 1, 1992 to Givens; U.S.Pat. No. 5,637,194, issued Jun. 10, 1997 to Ampulski et al.; U.S. Pat.No. 5,609.725, issued Mar. 11, 1997 to Phan; and U.S. Pat. No.5,628,876, issued May 13, 1997 to Ayers et al., the disclosures of whichpatents are incorporated herein by reference.

A suitable tissue substrate 10 has a basis weight of about 7 to 25pounds per 3,000 square feet per ply, preferably about 8 to 10 poundsper 3,000 square feet per ply, and most preferably about 8½ pounds per3,000 square feet per ply for bath tissue applications, and about 18 to22 pounds per 3,000 square feet per ply for hard surface cleaningapplications. A multi-basis weight substrate 10 is feasible for theclaimed invention. A multi-basis weight substrate 10 has regions of highand low basis weight juxtaposed together, and optionally intermediatebasis weight regions. The high basis weight regions provide strength.The low basis weight regions provide for transfer of water released fromthe emulsion to the surface. In a degenerate case, the low basis weightregions may be apertures, to increase the transfer of water to thesurface. If a multi-basis weight substrate 10 is used, the macro-basisweight of the substrate 10, averaging both high and low basis weightregions or high, intermediate and low basis weight regions, isconsidered.

If a multi-basis weight substrate 10 is desired, such a substrate 10 maybe made according to commonly assigned U.S. Pat. No. 5,277,761, issuedJan. 11, 1994 to Phan et al.; U.S. Pat. No. 5,443,691, issued Aug. 22,1995 to Phan et al.; and U.S. Pat. No. 5,614,061, issued Mar. 25, 1997to Phan et al., the disclosures of which patents are incorporated hereinby reference. If a multi-basis weight substrate 10 having radiallyoriented fibers is desired, such a substrate 10 may be made according tocommonly assigned U.S. Pat. Nos. 5,245,025, issued Sep. 14, 1993 toTrokhan et al.; U.S. Pat. No. 5,503,715, issued Apr. 2, 1996 to Trokhanet al.; U.S. Pat. No. 5,527,428, issued Jun. 18, 1996 to Trokhan et al.;or U.S. Pat. No. 5,534,326, issued Jul. 9, 1996 to Trokhan et al., thedisclosures of which patents are incorporated herein by reference.

If one desires to use a more durable or nonwoven substrate 10 for a wipe8, such a substrate 10 may be made according to commonly owned U.S. Pat.Nos. 4,097,965, issued Jul. 4, 1978 to Gotchel et al.; U.S. Pat. No.4,130,915, issued Dec. 26, 1978 to Gotchel et al.; U.S. Pat. No.4,296,161, issued Oct. 20, 1981 to Kaiser et al.; and U.S. Pat. No.4,682,942, issued Jul. 28, 1987 to Gotchel et al., the disclosures ofwhich patents are incorporated herein by reference.

The Emulsion

The emulsion 12 comprises: (1) a continuous solidified lipid phase; (2)an emulsifier that forms the emulsion 12 when the lipid phase is fluid;and

(3) an internal polar phase dispersed in the lipid phase. This emulsion12 ruptures when subjected to low shear during use, e.g., wiping of theskin or other surface, so as to release the internal polar phase.

1. External Lipid Phase

The continuous solidified lipid phase provides the essential stabilizingstructure for the high internal phase inverse emulsions 12 of thepresent invention. In particular, this continuous lipid phase is whatkeeps the dispersed internal phase from being prematurely released priorto use of the article, such as during storage.

The continuous lipid phase can comprise from about 2 to about 60% of theemulsion 12 of the present invention. Preferably, this continuous lipidphase will comprise from about 5 to about 30% of the emulsion 12. Mostpreferably, this lipid phase will comprise from about 6 to about 15% ofthe emulsion 12.

The major constituent of this continuous lipid phase is a waxy lipidmaterial. This lipid material is characterized by a melting point ofabout 30° C. or higher, i.e., is solid at ambient temperatures.Preferably, the lipid material has a melting point of about 50° C. orhigher. Typically, the lipid material has a melting point in the rangeof from about 40° to about 80° C., more typically in the range of fromabout 50° to about 70° C.

Although this waxy lipid material is solid at ambient temperatures, italso needs to be fluid or plastic at those temperatures at which thehigh internal phase inverse emulsion 12 is applied to the carrier.Moreover, even though the lipid material is fluid or plastic at thosetemperatures at which the emulsion 12 is applied to the carriersubstrate 10, it should still desirably be somewhat stable (i.e.,minimal coalescence of emulsion 12 micro-droplets) for extended periodsof time at elevated temperatures (e.g., about 50° C. or higher) that arenormally encountered during storage and distribution of the articles ofthe present invention. This lipid material also needs to be sufficientlybrittle at the shear conditions of use of the article such that itruptures and releases the dispersed internal polar phase. These lipidmaterials should also desirably provide a good feel to the skin whenused in personal care products such as wet-like cleansing wipes 8 andtissue used in perianal cleaning.

Suitable waxy lipid materials for use in the high internal phase inverseemulsion 12 of the present invention include natural and syntheticwaxes, as well as other oil soluble materials having a waxy consistency.As used herein, the term “waxes” refers to organic mixtures or compoundsthat are generally water-insoluble and tend to exist as amorphous ormicrocrystalline or crystalline solids at ambient temperatures (e.g., atabout 25° C.). Suitable waxes include various types of hydrocarbons, aswell as esters of certain fatty acids and fatty alcohols. They can bederived from natural sources (i.e., animal, vegetable or mineral) orthey can be synthesized. Mixtures of these various waxes can also beused.

Some representative animal and vegetable waxes that can be used in thepresent invention include beeswax, carnauba, spermaceti, lanolin,shellac wax, candelilla, and the like. Particularly preferred animal andvegetable waxes are beeswax, lanolin and candelilla. Representativewaxes from mineral sources that can be used in the present inventioninclude petroleum-based waxes such as paraffin, petrolatum andmicrocrystalline wax, and fossil or earth waxes such as white ceresinewax, yellow ceresine wax, white ozokerite wax, and the like.Particularly preferred mineral waxes are petrolatum, microcrystallinewax, yellow ceresine wax, and white ozokerite wax. Representativesynthetic waxes that can be used in the present invention includeethylenic polymers such as polyethylene wax, chlorinated naphthalenessuch as “Halowax,” hydrocarbon type waxes made by Fischer-Tropschsynthesis, and the like. Particularly preferred synthetic waxes arepolyethylene waxes.

Besides the waxy lipid material, the continuous lipid phase can includeminor amounts of other lipophilic or lipid-miscible materials. Theseother lipophilic/lipid-miscible materials are typically included for thepurpose of stabilizing the emulsion 12 to minimize loss of the internalpolar phase or for improving the aesthetic feel of the emulsion 12 onthe skin. Suitable materials of this type that can be present in thecontinuous lipid phase include hot melt adhesives such as Findley193-336 resin, long chain alcohols such as cetyl alcohol, stearylalcohol, and cetaryl alcohol, water-insoluble soaps such as aluminumstearate, silicone polymers such as polydimethylsiloxanes,hydrophobically modified silicone polymers such as phenyl trimethicone,and the like. Other suitable lipophilic/lipid miscible materials includepolyol polyesters. By “polyol polyester” is meant a polyol having atleast 4 ester groups. By “polyol” is meant a polyhydric alcoholcontaining at least 4, preferably from 4 to 12, and, most preferablyfrom 6 to 8, hydroxyl groups. Polyols include monosaccharides,disaccharides and trisaccharides, sugar alcohols and other sugarderivatives (e.g., alkyl glycosides), polyglycerols (e.g., diglyceroland triglycerol), pentaerythritol, and polyvinyl alcohols. Preferredpolyols include xylose, arabinose, ribose, xylitol, erythritol, glucose,methyl glucoside, mannose, galactose, fructose, sorbitol, maltose,lactose, sucrose, raffinose, and maltotriose. Sucrose is an especiallypreferred polyol. With respect to the polyol polyesters useful herein,it is not necessary that all of the hydroxyl groups of the polyol beesterified, however disaccharide polyesters should have no more than 3,and more preferably no more than 2 unesterified hydroxyl groups.Typically, substantially all (e.g., at least about 85%) of the hydroxylgroups of the polyol are esterified. In the case of sucrose polyesters,typically from about 7 to 8 of the hydroxyl groups of the polyol areesterified.

By “liquid polyol polyester” is meant a polyol polyester from thehereinbefore described groups having a fluid consistency at or belowabout 37° C. By “solid polyol polyester” is meant a polyol polyesterfrom the hereinbefore described groups having a plastic or solidconsistency at or above about 37° C. Liquid polyol polyesters and solidpolyol polyesters may be successfully employed as emollients andimmobilizing agents, respectively, in emulsions 12 of the presentinvention. In some cases, solid polyol polyesters may also provide someemolliency functionality.

2. Internal Polar Phase

Typically, the major component of the high internal phase inverseemulsions 12 of the present invention is the dispersed internal polarphase. 1l >In preferred embodiments, the polar phase will contain asignificant percentage of water, preferably at least about 60%, byweight of the emulsion 12, more preferably at least about 75%, byweight, still more preferably at least about 90%, by weight.

The internal polar phase can provide a number of different benefits whenreleased. For example, in wet-like cleaning wipes 8 for perianalcleaning where the internal polar phase is water, it is this releasedwater that provides the primary cleansing action for these wipes 8.

In a preferred embodiment of the present invention, the internal polarphase (preferably comprising water as a major constituent) is adisinfecting polar phase comprising an antimicrobial compound,preferably an essential oil or an active thereof, and a bleach,preferably a peroxygen bleach. Disinfecting wipes 8 comprising such aninternal disinfecting polar phase provide effective disinfectingperformance on a surface while being safe to the surface treated.

By “effective disinfecting performance” it is meant herein that thedisinfecting wipes 8 of the present invention allow significantreduction in the amount of bacteria on an infected surface. Indeed,effective disinfection may be obtained on various microorganismsincluding Gram positive bacteria like Staphylococcus aureus, and Gramnegative bacteria like Pseudomonas aeruginosa, as well as on moreresistant micro-organisms like fungi (e.g., Candida albicans) present oninfected surfaces.

Another advantage of the disinfecting wipes 8 according to the presentinvention is that besides the disinfection properties delivered, goodcleaning is also provided as the disinfecting polar phase may furthercomprise surfactants and/or solvents.

An essential element of the preferred internal disinfecting polar phaseis an antimicrobial compound typically selected from the groupconsisting of an essential oil and an active thereof, paraben (e.g.,methyl paraben, ethyl paraben), glutaraldehyde and mixtures thereof.Essential oils or actives thereof are the preferred antimicrobialcompounds to be used herein.

Suitable essential oils or actives thereof to be used herein are thoseessential oils which exhibit antimicrobial activity and moreparticularly antibacterial activity. By “actives of essential oils” itis meant herein any ingredient of essential oils that exhibitsantimicrobial/antibacterial activity. A further advantage of saidessential oils and actives hereof is that they impart pleasant odor tothe disinfecting wipes 8 according to the present invention without theneed of adding a perfume. Indeed, the disinfecting wipes 8 according tothe present invention deliver not only excellent disinfectingperformance on infected surfaces but also good scent.

Such essential oils include, but are not limited to, those obtained fromthyme, lemongrass, citrus, lemons, oranges, anise, clove, aniseed,cinnamon, geranium, roses, mint, lavender, citronella, eucalyptus,peppermint, camphor, sandalwood and cedar and mixtures thereof. Activesof essential oils to be used herein include, but are not limited to,thymol (present for example in thyme), eugenol (present for example incinnamon and clove), menthol (present for example in mint), geraniol(present for example in geranium and rose), verbenone (present forexample in vervain), eucalyptol and pinocarvone (present in eucalyptus),cedrol (present for example in cedar), anethol (present for example inanise), carvacrol, hinokitiol, berberine, terpineol, limonene, methylsalycilate and mixtures thereof. Preferred actives of essential oils tobe used herein are thymol, eugenol, verbenone, eucalyptol, carvacrol,limonene and/or geraniol. Thymol may be commercially available forexample from Aldrich, eugenol may be commercially available for examplefrom Sigma, Systems—Bioindustries (SBI)—Manheimer Inc.

Typically, the antimicrobial compound or mixtures thereof will bepresent in the internal polar phase at a level of from 0.001% to 5%,preferably from 0.001% to 3%, more preferably from 0.005% to 1%, byweight of total internal polar phase.

An important element of the internal disinfecting polar phase is ableach or mixtures thereof. Any bleach known to those skilled in the artmay be suitable to be used herein including any chlorine bleach as wellas any peroxygen bleach. The presence of the bleach, preferably theperoxygen bleach, in the disinfecting wipes 8 of the present inventioncontribute to the disinfection properties of the wipes 8.

Suitable chlorine bleaches to be used herein include any compoundcapable of releasing chlorine when said compound is in contact withwater. Suitable chlorine bleaches include alkali metaldichloroisocyanurates as well as alkali metal hypohalites likehypochlorite and/or hypobromite. Preferred chlorine bleaches are alkalimetal hypochlorites. Various forms of alkali metal hypochlorite arecommercially available, for instance sodium hypochlorite.

Preferred bleaches for use herein are peroxygen bleaches, moreparticularly hydrogen peroxide, or a water soluble source thereof, ormixtures thereof. Hydrogen peroxide is particularly preferred.

Peroxygen bleaches like hydrogen peroxide are preferred herein as theyare generally well accepted from an environmental point of view. Forexample the decomposition products of hydrogen peroxide are oxygen andwater.

As used herein, a hydrogen peroxide source refers to any compound whichproduces perhydroxyl ions when said compound is in contact with water.Suitable water-soluble sources of hydrogen peroxide for use hereininclude percarbonates, persilicates, persulphates such asmonopersulfate, perborates, peroxyacids such as diperoxydodecandioicacid (DPDA), magnesium perphthalic acid, dialkylperoxides,diacylperoxides, performed percarboxylic acids, organic and inorganicperoxides and/or hydroperoxides and mixtures thereof.

Typically, the bleach or mixtures thereof is present at a level of from0.001% to 15% by weight of the total internal polar phase, preferablyfrom 0.001% to 5%, and more preferably from 0.005% to 2%.

The internal disinfecting polar phase may further comprise a detersivesurfactant or a mixture thereof. Typically, the surfactant or mixturesthereof is present at a level of from 0.001% to 40% by weight of thetotal internal polar phase, preferably from 0.01% to 10% and morepreferably from 0.05% to 2%.

Suitable detersive surfactants to be used in the present inventioninclude any surfactant known to those skilled in the art like nonionic,anionic, cationic, amphoteric and/or zwitterionic surfactants. Preferreddetersive surfactants to be used herein are the amphoteric and/orzwitterionic surfactants.

Suitable amphoteric detersive surfactants to be used herein includeamine oxides of the formula R¹R²R³NO, wherein each of R¹, R² and R³ isindependently a saturated, substituted or unsubstituted, linear orbranched hydrocarbon chain having from 1 to 30 carbon atoms. Preferredamine oxide surfactants to be used according to the present inventionare amine oxides of the formula R¹R²R³NO, wherein R¹ is an hydrocarbonchain having from 1 to 30 carbon atoms, preferably from 6 to 20, morepreferably from 8 to 16, most preferably from 8 to 12, and wherein R²and R³ are independently substituted or unsubstituted, linear orbranched hydrocarbon chains having from 1 to 4 carbon atoms, preferablyfrom 1 to 3 carbon atoms, and more preferably are methyl groups. R¹ maybe a saturated, substituted or unsubstituted, linear or branchedhydrocarbon chain. Suitable amine oxides for use herein are for instancenatural blend C₈-C₁₀ amine oxides as well as C₁₂-C₁₆ amine oxidescommercially available from Hoechst. Amine oxides are preferred hereinas they deliver effective cleaning performance and further participateto the disinfecting properties of the disinfecting wipes 8 herein.

Suitable zwitterionic surfactants to be used herein contain bothcationic and anionic hydrophilic groups on the same molecule at arelatively wide range of pH's. The typical cationic group is aquaternary ammonium group, although other positively charged groups likephosphonium, imidazolinium and sulfonium groups can be used. The typicalanionic hydrophilic groups are carboxylates and sulfonates, althoughother groups such as sulfates, phosphonates, and the like can be used. Ageneric formula for some zwitterionic surfactants to be used herein is

R¹—N⁺(R²)(R³)R⁴ [X⁻]

wherein R¹ is a hydrophobic group; R² and R³ are each C₁-C₄ alkyl,hydroxy alkyl or other substituted alkyl group which can also be joinedto form ring structures with the N; R⁴ is a moiety joining the cationicnitrogen atom to the hydrophilic group and is typically an alkylene,hydroxy alkylene, or polyalkoxy group containing from 1 to 10 carbonatoms; and X is the hydrophilic group which is preferably a carboxylateor sulfonate group. Preferred hydrophobic groups R¹ are alkyl groupscontaining from 1 to 24, preferably less than 18, more preferably lessthan 16 carbon atoms. The hydrophobic group can contain unsaturationand/or substituents and/or linking groups such as aryl groups, amidogroups, ester groups and the like. In general, the simple alkyl groupsare preferred for cost and stability reasons.

Highly preferred zwitterionic surfactants include betaine andsulphobetaine surfactants, derivatives thereof or mixtures thereof. Saidbetaine or sulphobetaine surfactants are preferred herein as they helpdisinfection by increasing the permeability of the bacterial cell wall,thus allowing other active ingredients to enter the cell.

Furthermore, due to the mild action profile of said betaine orsulphobetaine surfactants, they are particularly suitable for thecleaning of delicate surfaces, e.g., hard surfaces in contact with foodand/or babies. Betaine and sulphobetaine surfactants are also extremelymild to the skin is and/or surfaces to be treated.

Suitable betaine and sulphobetaine surfactants to be used herein are thebetaine/sulphobetaine and betaine-like detergents wherein the moleculecontains both basic and acidic groups which form an inner salt givingthe molecule both cationic and anionic hydrophilic groups over a broadrange of pH values. Some common examples of these detergents aredescribed in U.S. Pat. Nos. 2,082,275, 2,702,279 and 2,255,082,incorporated herein by reference. Preferred betaine and sulphobetainesurfactants herein are according to the formula

wherein R¹ is a hydrocarbon chain containing from 1 to 24 carbon atoms,preferably from 8 to 18, more preferably from 12 to 14, wherein R² andR³ are hydrocarbon chains containing from 1 to 3 carbon atoms,preferably 1 carbon atom, wherein n is an integer from 1 to 10,preferably from 1 to 6, more preferably is 1, Y is selected from thegroup consisting of carboxyl and sulfonyl radicals and wherein the sumof R¹, R² and R³ hydrocarbon chains is from 14 to 24 carbon atoms, ormixtures thereof.

Examples of particularly suitable betaine surfactants include C₁₂-C₁₈alkyl dimethyl betaine such as coconut-betaine and C₁₀-C₁₆ alkyldimethyl betaine such as laurylbetaine. Coconutbetaine is commerciallyavailable from Seppic under the trade name of Amonyl 265®. Laurylbetaineis commercially available from Albright & Wilson under the trade nameEmpigen BB/L®.

Other specific zwitterionic surfactants have the generic formulas:

wherein each R¹ is a hydrocarbon, e.g. an alkyl group containing from 8up to 20, preferably up to 18, more preferably up to 16 carbon atoms,each R² is either a hydrogen (when attached to the amido nitrogen),short chain alkyl or substituted alkyl containing from 1 to 4 carbonatoms, preferably groups selected from the group consisting of methyl,ethyl, propyl, hydroxy substituted ethyl or propyl and mixtures thereof,preferably methyl, each R³ is selected from the group consisting ofhydrogen and hydroxy groups and each n is a number from 1 to 4,preferably from 2 to 3, more preferably 3, with no more than one hydroxygroup in any (C(R³)₂) moiety. The R₁ groups can be branched and/orunsaturated. The R² groups can also be connected to form ringstructures. A surfactant of this type is a C₁₀-C₁₄ fattyacylamidopropylene-(hydroxypropylene)sulfobetaine that is available fromthe Sherex Company under the trade name “Varion CAS sulfobetaine®.

Suitable nonionic surfactants to be used herein are fatty alcoholethoxylates and/or propoxylates which are commercially available with avariety of fatty alcohol chain lengths and a variety of ethoxylationdegrees. Indeed, the HLB values of such alkoxylated nonionic surfactantsdepend essentially on the chain length of the fatty alcohol, the natureof the alkoxylation and the degree of alkoxylation. Surfactantcatalogues are available which list a number of surfactants, includingnonionics, together with their respective HLB values.

Particularly suitable for use herein as nonionic surfactants are thehydrophobic nonionic surfactants having an HLB (hydrophilic-lipophilicbalance) below 16 and more preferably below 15. Those hydrophobicnonionic surfactants have been found to provide good grease cuttingproperties.

Preferred nonionic surfactants for use herein are nonionic surfactantsaccording to the formula RO—(C₂H₄O)_(n)(C₃H₆O)_(m)H, wherein R is a C₆to C₂₂ alkyl chain or a C₆ to C₂₈ alkyl benzene chain, and wherein n+mis from 0 to 20 and n is from 0 to 15 and m is from 0 to 20, preferablyn+m is from 1 to 15 and n and m are from 0.5 to 15, more preferably n+mis from 1 to 10 and n and m are from 0 to 10. The preferred R chains foruse herein are the C₈ to C₂₂ alkyl chains. Accordingly, suitablehydrophobic nonionic surfactants for use herein are Dobanol R 91-2.5(HLB=8.1; R is a mixture of C₉ and C₁₁ alkyl chains, n is 2.5 and m is0), or Lutensol R TO3 (HLB=8; R is a C13 alkyl chains, n is 3 and m is0), or Lutensol R AO3 (HLB=8; R is a mixture of C₁₃ and C₁₅ alkylchains, n is 3 and m is 0), or Tergitol R 25L3 (HLB=7.7; R is in therange of C₁₂ to C₁₅ alkyl chain length, n is 3 and m is 0), or Dobanol R23-3 (HLB=8.1; R is a mixture of C₁₂ and C₁₃ alkyl chains, n is 3 and mis 0), or Dobanol R 23-2 (HLB=6.2; R is a mixture of C₁₂ and C₁₃ alkylchains, n is 2 and m is 0), or Dobanol R 45-7 (HLB=11.6; R is a mixtureof C₁₄ and C₁₅ alkyl chains, n is 7 and m is 0) Dobanol R 23-6.5(HLB=11.9; R is a mixture of C₁₂ and C₁₃ alkyl chains, n is 6.5 and m is0), or Dobanol R 25-7 (HLB=12; R is a mixture Of C₁₂ and C₁₅ alkylchains, n is 7 and m is 0), or Dobanol R 91-5 (HLB=11.6; R is a mixtureof C₉ and C₁₁ alkyl chains, n is 5 and m is 0), or Dobanol R 91-6(HLB=12.5; R is a mixture of C₉ and C₁₁ alkyl chains, n is 6 and m is0), or Dobanol R 91-8 (HLB=13.7; R is a mixture of C₉ and C₁₁ alkylchains, n is 8 and m is 0), Dobanol R 91-10 (HLB=L14.2; R is a mixtureof C₉ to C₁₁ alkyl chains, n is 10 and m is 0), or mixtures thereof.Preferred herein are Dobanol R 91-2.5, or Lutensol R TO3, or Lutensol RAO3, or Tergitol R 25L3, or Dobanol R 23-3, or Dobanol R 23-2, orDobanol R 23-10, or mixtures thereof. DobanolR surfactants arecommercially available from SHELL. LutensolR surfactants arecommercially available from BASF and the Tergitol R surfactants arecommercially available from UNION CARBIDE.

Suitable anionic surfactants to be used herein include water solublesalts or acids of the formula ROSO₃M wherein R is preferably a C₆-C₂₄hydrocarbyl, preferably an alkyl or hydroxyalkyl having a C₈-C₂₀ alkylcomponent, more preferably a C₈-C₁₈ alkyl or hydroxyalkyl, and M is H ora cation, e.g., an alkali metal cation (e.g., sodium, potassium,lithium), or ammonium or substituted ammonium (e.g., methyl-, dimethyl-,and trimethyl ammonium cations and quaternary ammonium cations, such astetramethyl-ammonium and dimethyl piperdinium cations and quaternaryammonium cations derived from alkylamines such as ethylamine,diethylamine, triethylamine, and mixtures thereof, and the like).

Other suitable anionic surfactants to be used herein includealkyldiphenyl-ether-sulphonates and alkyl-carboxylates. Other anionicsurfactants can include salts (including, for example, sodium,potassium, ammonium, and substituted ammonium salts such as mono-, di-and triethanolamine salts) of soap, C₉-C₂₀ linearalkylbenzenesulfonates, C₈-C₂₂ primary or secondary alkanesulfonates,C₈-C₂₄ olefinsulfonates, sulfonated polycarboxylic acids prepared bysulfonation of the pyrolyzed product of alkaline earth metal citrates,e.g., as described in British patent specification No. 1,082,179, C₈-C₂₄alkylpolyglycolethersulfates (containing up to 10 moles of ethyleneoxide); alkyl ester sulfonates such as C₁₄₋₁₆ methyl ester sulfonates;acyl glycerol sulfonates, fatty oleyl glycerol sulfates, alkyl phenolethylene oxide ether sulfates, paraffin sulfonates, alkyl phosphates,isethionates such as the acyl isethionates, N-acyl taurates, alkylsuccinamates and sulfosuccinates, monoesters of sulfosuccinate(especially saturated and unsaturated C₁₂-C₁₈ monoesters) diesters ofsulfosuccinate (especially saturated and unsaturated C₆-C₁₄ diesters),acyl sarcosinates, sulfates of alkylpolysaccharides such as the sulfatesof alkylpolyglucoside (the nonionic nonsulfated compounds beingdescribed below), branched primary alkyl sulfates, alkyl polyethoxycarboxylates such as those of the formula RO(CH₂CH₂O)_(k)CH₂COO—M+wherein R is a C₈-C₂₂ alkyl, k is an integer from 0 to 10, and M is asoluble salt-forming cation. Resin acids and hydrogenated resin acidsare also suitable, such as rosin, hydrogenated rosin, and resin acidsand hydrogenated resin acids present in or derived from tall oil.Further examples are given in “Surface Active Agents and Detergents”(Vol. I and II by Schwartz, Perry and Berch). A variety of suchsurfactants are also generally disclosed in U.S. Pat. No. 3,929,678,issued Dec. 30, 1975 to Laughlin, et al. at Column 23, line 58 throughColumn 29, line 23 (herein incorporated by reference).

Preferred anionic surfactants for use herein are the alkyl benzenesulfonates, alkyl sulfates, alkyl alkoxylated sulfates, paraffinsulfonates and mixtures thereof.

The internal disinfecting polar phase according to the present inventionhas a pH of from 1 to 12, preferably from 3 to 10, and more preferablyfrom 3 to 9. The pH can be adjusted by using alkalinizing agents oracidifying agents. Examples of alkalinizing agents are alkali metalhydroxides, such as potassium and/or sodium hydroxide, or alkali metaloxides such as sodium and/or potassium oxide. Examples of acidifyingagents are organic or inorganic acids such as citric or sulfuric acid.

Solvents may be present in the internal disinfecting polar phaseaccording to the present invention. These solvents will, advantageously,give an enhanced cleaning to the disinfecting wipes 8 of the presentinvention. Suitable solvents for incorporation herein include propyleneglycol derivatives such as n-butoxypropanol or n-butoxypropoxypropanol,water-soluble CARBITOL® solvents or water-soluble CELLOSOLVE® solvents.Water-soluble CARBITOL® solvents are compounds of the2-(2-alkoxyethoxy)ethanol class wherein the alkoxy group is derived fromethyl, propyl or butyl. A preferred water-soluble carbitol is2-(2-butoxyethoxy)ethanol also known as butyl carbitol. Water-solubleCELLOSOLVE® solvents are compounds of the 2-alkoxyethoxyethanol class,with 2-butoxyethoxyethanol being preferred. Other suitable solvents arebenzyl alcohol, methanol, ethanol, isopropyl alcohol and diols such as2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol and mixturethereof. Preferred solvents for use herein are n-butoxypropoxypropanol,butyl carbitol® and mixtures thereof. A most preferred solvent for useherein is butyl carbitol®.

The internal disinfecting polar phase herein may further comprise otheroptional ingredients including radical scavengers, chelating agents,thickeners, builders, buffers, stabilizers, bleach activators, soilsuspenders, dye transfer agents, brighteners, anti dusting agents,enzymes, dispersant, dye transfer inhibitors, pigments, perfumes, anddyes and the like.

Suitable radical scavengers for use herein include the well-knownsubstituted mono and di hydroxy benzenes and derivatives thereof, alkyl-and aryl carboxylates and mixtures thereof. Preferred radical scavengersfor use herein include di-tert-butyl hydroxy toluene (BHT),p-hydroxytoluene, hydroquinone (HQ), di-tert-butyl hydroquinone (DTBHQ),mono-tert-butyl hydroquinone (MTBHQ), tert-butyl-hydroxy anysole,p-hydroxyanysol, benzoic acid, 2,5-dihydroxy benzoic acid,2,5-dihydroxyterephtalic acid, toluic acid, catechol, t-butyl catechol,4-allyl-catechol, 4-acetyl catechol, 2-methoxy-phenol, 2-ethoxy-phenol,2-methoxy4-(2-propenyl)phenol, 3,4-dihydroxy benzaldehyde, 2,3-dihydroxybenzaldehyde, benzylamine,1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl) butane,tert-butyl-hydroxy-anyline, p-hydroxy anyline as well asn-propyl-gallate. Highly preferred for use herein is di-tert-butylhydroxy toluene, which is for example commercially available from SHELLunder the trade name IONOL CP®.

Typically, the radical scavenger, or a mixture thereof, is present inthe internal water phase up to a level of 5% by weight, preferably from0.001% to 3% by weight, and more preferably from 0.001% to 1.5%.

Suitable chelating agents to be used herein may be any chelating agentknown to those skilled in the art such as the ones selected from thegroup consisting of phosphonate chelating agents, amino carboxylatechelating agents or other carboxylate chelating agents, orpolyfunctionally-substituted aromatic chelating agents and mixturesthereof.

Such phosphonate chelating agents may include etidronic acid(1-hydroxyethylidene-bisphosphonic acid or HEDP) as well as aminophosphonate compounds, including amino alkylene poly (alkylenephosphonate), alkali metal ethane 1-hydroxy diphosphonates, nitrilotrimethylene phosphonates, ethylene diamine tetra methylenephosphonates, and diethylene triamine penta methylene phosphonates. Thephosphonate compounds may be present either in their acid form or assalts of different cations on some or all of their acid functionalities.Preferred phosphonate chelating agents to be used herein are diethylenetriamine penta methylene phosphonates. Such phosphonate chelating agentsare commercially available from Monsanto under the trade name DEQUEST®.

Polyfunctionally-substituted aromatic chelating agents may also beuseful herein. See U.S. Pat. No. 3,812,044, issued May 21, 1974, toConnor et al. Preferred compounds of this type in acid form aredihydroxydisulfobenzenes such as 1,2-dihydroxy-3,5-disulfobenzene.

A preferred biodegradable chelating agent for use herein is ethylenediamine N,N′-disuccinic acid, or alkali metal, or alkaline earth,ammonium or substitutes ammonium salts thereof or mixtures thereof.Ethylenediamine N,N′-disuccinic acids, especially the (S,S) isomer havebeen extensively described in U.S. Pat. No. 4,704,233, Nov. 3, 1987 toHartman and Perkins. Ethylenediamine N,N′-disuccinic acid is, forinstance, commercially available under the tradename ssEDDS® from PalmerResearch Laboratories.

Suitable amino carboxylate chelating agents useful herein includeethylene diamine tetra acetate, diethylene triamine pentaacetate,diethylene triamine pentaacetate (DTPA), N-hydroxyethylethylenediaminetriacetate, nitrilotri-acetate, ethylenediamine tetraproprionate,triethylenetetraaminehexa-acetate, ethanoldiglycine, propylene diaminetetracetic acid (PDTA) and methyl glycine di-acetic acid (MGDA), both intheir acid form, or in their alkali metal, ammonium, and substitutedammonium salt forms. Particularly suitable to be used herein arediethylene triamine penta acetic acid (DTPA), propylene diaminetetracetic acid (PDTA) which is, for instance, commercially availablefrom BASF under the trade name Trilon FS® and methyl glycine di-aceticacid (MGDA).

Further carboxylate chelating agents to be used herein includes malonicacid, salicylic acid, glycine, aspartic acid, glutamic acid, dipicolinicacid and derivatives thereof, or mixtures thereof.

Typically, the chelating agent, or a mixture thereof, is present in theinternal polar phase at a level of from 0.001% to 5% by weight,preferably from 0.001% to 3% by weight and more preferably from 0.001%to 1.5%.

The disinfecting wipes 8 according to the present invention are suitablefor disinfecting various surfaces including animate surfaces (e.g. humanskin) as well as inanimate surfaces including any hard-surfaces.

Regardless of its composition, the internal polar phase will preferablycomprise from about 67 to about 92% of the emulsion 12. Most preferably,the internal polar phase will comprise from about 82 to about 91% of theemulsion 12.

Where the internal polar phase comprises water as a major component, theinternal phase can comprise water-soluble or dispersible materials thatdo not adversely affect the stability of the high internal phase inverseemulsion 12. One such material that is typically included in theinternal water phase is a water-soluble electrolyte. The dissolvedelectrolyte minimizes the tendency of materials present in the lipidphase to also dissolve in the water phase. Any electrolyte capable ofimparting ionic strength to the water phase can be used. Suitableelectrolytes include the water soluble mono-, di-, or trivalentinorganic salts such as the water-soluble halides, e.g., chlorides,nitrates and sulfates of alkali metals and alkaline earth metals.Examples of such electrolytes include sodium chloride, calcium chloride,sodium sulfate, magnesium sulfate, and sodium bicarbonate. Theelectrolyte will typically be included in a concentration in the rangeof from about 1 to about 20% of the internal water phase.

Other water-soluble or dispersible materials that can be present in theinternal polar phase include thickeners and viscosity modifiers.Suitable thickeners and viscosity modifiers include polyacrylic andhydrophobically modified polyacrylic resins such as Carbopol andPemulen, starches such as corn starch, potato starch, tapioca, gums suchas guar gum, gum arabic, cellulose ethers such as hydroxypropylcellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and thelike. These thickeners and viscosity modifiers will typically beincluded in a concentration in the range of from about 0.05 to about0.5% of the internal phase.

Again, where water is a major constituent of the internal polar phase,water-soluble or dispersible materials that can be present in theinternal phase include polycationic polymers to provide stericstabilization at the polar phase-lipid phase interface and nonionicpolymers that also stabilize the emulsion 12. Suitable polycationicpolymers include Reten 201, Kymene® 557H and Acco 711. Suitable nonionicpolymers include polyethylene glycols (PEG) such as Carbowax. Thesepolycationic and nonionic polymers will typically be included in aconcentration in the range of from about 0.1 to about 1.0% of the polarphase.

3. Emulsifier

Another key component of the high internal phase inverse emulsion 12 ofthe present invention is an emulsifier. In the emulsions 12 of thepresent invention, the emulsifier is included in an effective amount.What constitutes an “effective amount” will depend on a number offactors including the respective amounts of the lipid and internal polarphase components, the type of emulsifier used, the level of impuritiespresent in the emulsifier, and like factors. Typically, the emulsifiercomprises from about 1 to about 10% of the emulsion 12. Preferably, theemulsifier will comprise from about 3 to about 6% of the emulsion 12.Most preferably, the emulsifier will comprise from about 4 to about 5%of the emulsion 12. While the singular “emulsifier” is used to describethis component, more than one emulsifier may be used when forming theemulsion 12. Indeed, as discussed below, it may be desirable to utilizeboth a primary and a secondary emulsifier when certain materials areemployed. Though not intended to limit the scope of the invention, wheretwo emulsifiers are utilized, preferred is where the primary emulsifiercomprises from about 1 to about 7%, more preferably from about 2 toabout 5%, most preferably from about 2 to about 4%, by weight of theemulsion 12; and the secondary emulsifier comprises from about 0.5 toabout 3%, more preferably from about 0.75 to about 2%, most preferablyfrom about 0.75 to about 1.5%, by weight of the emulsion 12.

The emulsifier needs to be substantially lipid-soluble or miscible withthe lipid phase materials, especially at the temperatures at which thelipid material melts. It also should have a relatively low HLB value.Emulsifiers suitable for use in the present invention have HLB valuestypically in the range of from about 2 to about 5 and can includemixtures of different emulsifiers. Preferably, these emulsifiers willhave HLB values in the range of from about 2.5 to about 3.5.

Preferred emulsifiers for use in the present invention include siliconepolymer emulsifiers such as alkyl dimethicone copolyols (e.g., DowCorning Q2-5200 laurylmethicone copolyol). Such emulsifiers aredescribed in detail in co-pending U.S. patent application Ser. No.08/767,120, filed Jan. 14, 1997 by L. Mackey (Case 5653C), now U.S. Pat.No. 5,765,112, which is incorporated by reference herein.

Other suitable emulsifiers are described in co-pending U.S. patentapplication Ser. No. 08/336,456, filed Nov. 9, 1994 by L. Mackey et al.(Case 5478), now abandoned, and U.S. patent application Ser. No.08/761,097, filed Dec. 5, 1996 by L. Mackey et al. (Case 5478R), nowU.S. Pat. No. 5,863,663, both of which are incorporated by referenceherein. Emulsifiers described therein include certain sorbitan esters,preferably the sorbitan esters of C₁₆-C₂₂ saturated, unsaturated orbranched chain fatty acids. Because of the manner in which they aretypically manufactured, these sorbitan esters usually comprise mixturesof mono-, di-, tri-, etc. esters. Representative examples of suitablesorbitan esters include sorbitan monooleate (e.g., SPAN® 80), sorbitansesquioleate (e.g., Arlacel® 83), sorbitan monoisostearate (e.g., CRILL®6 made by Croda), sorbitan stearates (e.g., SPAN® 60), sorbitantriooleate (e.g., SPAN® 85), sorbitan tristearate (e.g., SPAN® 65) andsorbitan dipalmitates (e.g., SPAN® 40). Laurylmethicone copolyol is aparticularly preferred emulsifier for use in the present invention.Other suitable emulsifiers described therein include certain glycerylmonoesters, preferably glyceryl monoesters of C₁₆-C₂₂ saturated,unsaturated or branched chain fatty acids such as glyceryl monostearate,glyceryl monopalmitate, and glyceryl monobehenate; certain sucrose fattyacid esters, preferably sucrose esters of the C₁₂-C₂₂ saturated,unsaturated, and branched chain fatty acids such as sucrose trilaurateand sucrose distearate (e.g., Crodesta® F10), and certain polyglycerolesters of C₁₆-C₂₂ saturated, unsaturated or branched fatty acids such asdiglycerol monooleate and tetraglycerol monooleate. In addition to theseprimary emulsifiers, coemulsifiers can be used to provide additionalwater-in-lipid emulsion 12 stability. Suitable coemulsifiers includephosphatidyl cholines and phosphatidyl choline-containing compositionssuch as the lecithins; long chain C₁₆-C₂₂ fatty acid salts such assodium stearate, long chain C₁₆-C₂₂ dialiphatic, short chain C₁-C₄dialiphatic quaternary ammonium salts such as ditallow dimethyl ammoniumchloride and ditallow dimethyl ammonium methylsulfate; long chainC₁₆-C₂₂ dialkoyl(alkenoyl)-2-hydroxyethyl, short chain C₁-C₄ dialiphaticquaternary ammonium salts such as ditallowoyl-2-hydroxyethyl dimethylammonium chloride, the long chain C₁₆-C₂₂ dialiphatic imidazoliniumquaternary ammonium salts such as methyl-1-tallow amido ethyl-2-tallowimidazolinium methylsulfate and methyl-1-oleyl amido ethyl-2-oleylimidazolinium methylsulfate; short chain C₁-C₄ dialiphatic, long chainC₁₆-C₂₂ monoaliphatic benzyl quaternary ammonium salts such as dimethylstearyl benzyl ammonium chloride, and synthetic phospholipids such asstearamidopropyl PG-dimonium chloride (Phospholipid PTS from MonaIndustries). Interfacial tension modifiers such as cetyl and stearylalcohol for closer packing at the water-lipid interface can also beincluded.

Other emulsifiers useful in making the articles of the present inventioninclude the high viscosity emulsifiers described in co-pending U.S.patent application Ser. No. 08/759,547, filed Dec. 5, 1996 by L. Mackeyand B. Hird, now U.S. Pat. No. 5,980,922, which is incorporated byreference herein. These emulsifiers preferably have a viscosity at 55°C. of at least about 500 centipoise. (Viscosity can be measured using aLab-Line Instruments Brookfield-type rotating disc viscometer.) Thatapplication describes specifically the use of emulsifiers such as thosedesignated by The Lubrizol Corporation (Wickliffe, Ohio) as OS-122102,OS-121863, OS-121864, OS-80541J and OS-80691J, which are reactionproducts of (i) a hydrocarbyl-substituted carboxylic acid or anhydride(preferably a polyisobutylene-substituted succinic acid or anhydride);and (ii) an amine or alcohol, to form an ester or amide product. Thematerials, and methods for their manufacture, are described in U.S. Pat.No. 4,708,753, issued Nov. 24, 1987 to Forsberg [see especially Column3, lines 32-38; and Column 8, line 10, to Column 26, line 68], and U.S.Pat. No. 4,844,756, issued Jul. 4, 1989 to Forsberg, both of which areincorporated by reference herein.

Other materials believed to be useful in the present invention includehydrocarbon-substituted succinic anhydrides such as those described inU.S. Pat. No. 3,215,707, issued Nov. 2, 1965 to Rense; U.S. Pat. No.3,231,587, issued Jan. 25, 1996 to Rense; U.S. Pat. No. 5,047,175,issued to Forsberg on Sep. 10, 1991; and World Patent Publication NumberWO 87/03613, published by Forsberg on Jun. 18, 1987. These publicationsare all incorporated by reference herein.

Still other materials useful as the emulsifier, particularly as aco-emulsifier with a high viscosity primary emulsifier, are ABA blockcopolymers of 12-hydroxystearic acid and polyethylene oxide. Suchmaterials are described in U.S. Pat. No. 4,875,927, issued to T. Tadroson Oct. 24, 1989, which is incorporated by reference herein. Arepresentative material of this class useful as an emulsifier herein isavailable from Imperial Chemical Industries PLC as Arlacel P135.

While all the above-described materials may be used as a singleemulsifier, it may be desired to employ more than one emulsifier whenforming the emulsion 12. In particular, where a high viscosityemulsifier is used, a certain “tacky” feel may result when the treatedarticle is subjected to in-use shear pressures that break the emulsion12. In this case, it may be desirable to use a relatively lowerviscosity co-emulsifier with the primary emulsifier, to allow use of alower amount of the main emulsifier, thereby alleviating tackiness. Inone preferred embodiment of the present invention, a primary emulsifieravailable from Lubrizol (i.e., reaction product ofpolyisobutylene-substituted succinic acid and an amine) and a secondaryemulsifier that is an ABA block copolymer of poly-12-hydroxystearic acidand polyethylene oxide (e.g., ICI's Arlacel P135) are used to provide anemulsion 12 with improved water retention levels over time, as well asbeneficial reduced tackiness (via reduction in level of primaryemulsifier). The skilled artisan will recognize that different desiredend-uses will dictate whether multiple emulsifiers are appropriate, andthe appropriate relative amounts of each if appropriate. Such adetermination will require only routine experimentation by the skilledartisan in view of the present disclosure.

4. Optional Emulsion Components

The high internal phase inverse emulsions 12 of the present inventioncan also comprise other optional components typically present inmoisture containing solutions of this type. These optional componentscan be present in either the continuous lipid phase or the internalpolar phase and include perfumes, antimicrobial (e.g., antibacterial)actives, pharmaceutical actives, deodorants, opacifiers, astringents,skin moisturizers, and the like, as well as mixtures of thesecomponents. All of these materials are well known in the art asadditives for such formulations and can be employed in effective,appropriate amounts in the emulsions 12 of the present invention. Aparticularly preferred optional component that is included in theemulsions 12 of wet-like cleansing wipes 8 according to the presentinvention is glycerin as a skin conditioning agent.

The emulsion 12 component of the articles of the present invention isdescribed and claimed herein in terms of components, and correspondingamounts of the components, that are present after emulsion 12 formation.That is, when the stable emulsion 12 is formed and applied to thecarrier. It is understood that the description (components and amounts)of the emulsion 12 also encompasses emulsions 12 formed by combining thedescribed components and levels, regardless of the chemical identity ofthe components after emulsification and application to the carrier.

C. Other Optional Article Components

Besides the high internal phase inverse emulsion 12, there are otheroptional components that can be included in the articles of the presentinvention, typically for the purpose of improving the cleaningperformance of the article when the internal polar phase of the emulsion12 is released. Certain of these optional components cannot be presentin the emulsion 12 at significant levels (e.g., greater than 2% of theinternal phase) because they can cause premature disruption of theemulsion 12. These include various anionic detergent surfactants thathave relatively high HLB values (e.g., HLBs of from about 10 to about25), such as sodium linear alkylbenzene sulfonates (LAS) or alkyl ethoxysulfates (AES), as well as nonionic detergent surfactants such as alkylethoxylates, alkyl amine oxides, alkyl polyglycosides, zwitterionicdetergent surfactants, ampholytic detergent surfactants, and cationicdetergent surfactants such as cetyl trimethyl ammonium salts, and lauryltrimethyl ammonium salts. See U.S. Pat. No. 4,597,898 (Vander Meer),issued Jul. 1, 1986 (herein incorporated by reference), especiallycolumns 12 through 16 for representative anionic, nonionic,zwitterionic, ampholytic and cationic detergent surfactants. Instead,these high HLB detergent surfactants can be applied or included in thearticle separately from the emulsion 12. For example, an aqueoussolution of these high HLB detergent surfactants can be applied to thecarrier either before or after application of the emulsion 12 to thecarrier. During wiping, the emulsion 12 is disrupted, releasing thepolar phase components so that they can then be combined with the highHLB detergent surfactant to provide improved hard surface cleaning.

Though the description of the invention generally relates to applying asingle water-in-lipid emulsion 12 to the carrier, it is recognized thattwo or more different emulsions 12 may be utilized in preparing a singlearticle. In such embodiments, the emulsions 12 may differ in a varietyof ways, including but not limited to, the ratio of the internal polarphase and the external lipid phase, the emulsifiers used, the componentsused for either or both of the internal and lipid phases, and the like.Utilization of multiple emulsions 12 in one article may be particularlydesirable when two or more components are incompatible with each other,but can each be included in a separate emulsion 12. Alternatively, if aparticular reaction is desired at the time of use, the reactants can beprovided in separate emulsions 12. Upon shearing of the emulsions 12during use, the desired reaction will occur. For example, where foamingis desired during the wiping processes, a mild acid can be incorporatedin the internal polar phase of one emulsion 12, while bicarbonate isincorporated in the internal polar phase of a second emulsion 12. Uponshearing of the emulsions 12 during use, the reactants interact toprovide the desired foam.

Suitable emulsion 12 descriptions are also found in the aforementionedcommonly assigned World Patent Applications WO 96/14835, published May23, 1996, in the names of Mackey et al.; and WO 96/21505, published Jul.18, 1996, in the name of DesMarais, incorporated herein by reference.

The Pattern

As noted above, the emulsion 12 is preferably applied to the substrate10 in a discontinuous pattern. As noted above, a discontinuous patternis one in which the emulsion 12 has distinct regions separated byregions 14 of the substrate 10 which are free of the emulsion 12.Suitable discontinuous patterns comprise discrete island regions of theemulsion 12, essentially continuous networks of emulsion 12, discretemacropatterns of the emulsion 12, and, preferably, discrete stripes ofthe emulsion 12 disposed in a semi-continuous pattern. The stripes arepreferably continuous, as illustrated, but may, alternatively, comprisea pattern of discrete segments which collectively comprise a stripe. Ifstripes are selected, the stripes are preferably oriented in the machinedirection, for ease of manufacture.

The emulsion 12 may be applied to and disposed on the substrate 10 byany suitable means well known in the art, such as gravure printing,flexographic printing, spraying, and preferably extruding. Morepreferably, the emulsion 12 is extruded as a series of continuouscylindrically shaped beads. A continuous cylindrical shape is preferredfor the emulsion 12 because this shape reduces the surface area tovolume ratio of the emulsion 12.

The stripes may be straight, as shown, may be sinusoidally shaped, etc.If sinusoidally shaped stripes are selected, preferably the stripes arein phase, so that parallelism is maintained and each stripe remainsequally spaced from the adjacent stripes.

It is desired that the emulsion 12 have the minimum possible surfacearea to volume ratio. Minimizing the surface area to volume ratioreduces water loss from the emulsion 12 due to evaporation. Preferablythe emulsion 12 has a surface area to volume ratio of less than or equalto 4/unit length, more preferably less than or equal to 3/unit length,and most preferably less than or equal to 2/unit length, wherein theunit length is measured in the cross section of the emulsion 12.Suitable surface area to volume ratios for cylindrical beads of emulsion12 range from 40 to 200 inches⁻¹ and preferably 75 to 125 inches⁻¹.

However, the optimum results are not achieved, for example, bypresenting a single, unitary sphere of emulsion 12 to the user with thewipe 8. Such an arrangement would likely provide adequate water.However, the water distribution would be highly localized and may notadequately spread throughout the surface area of the wipe 8. Preferably,the distribution of the emulsion 12, or, more particularly, the waterreleased therefrom, approximates the perception of a water spray ontothe skin.

It will be apparent to one skilled in the art that as the basis weightand absorbency of the substrate 10 increase, the amount of waternecessary to locally saturate the substrate 10 will likewise increase.Therefore, as the basis weight and/or absorbency of the substrate 10increases, the amount of emulsion 12 applied to the substrate 10 shouldincrease proportionately.

Preferably, 5 to 35 percent, and more preferably 10 to 25 percent of thesurface area of the wipe 8 has emulsion 12 disposed thereon. Uponrupture, the emulsion 12 locally wets corresponding regions of thesubstrate 10. The wetted portion of the substrate 10 may range from 10to 90 percent of the surface area of the substrate 10, with, of course,the balance of the surface area of the substrate 10 remaining dry due tothe discontinuous pattern.

It will be apparent that in use the percentage of wetted surface areawill be greater than the percentage of surface area initially coated bythe emulsion 12. It is to be further understood that, of course, theentire wipe 8 may be wetted as a function of the time and/or use of thewipe 8.

Thus, beads of emulsion 12 are preferably applied to the substrate 10 inan arrangement that accommodates both the diameter and pitch of thebeads in a preferred geometry. The amount of water carried by theemulsion 12 increases according to the square of the diameter of thebeads. Therefore, as the diameter of the beads increases, the pitchbetween adjacent stripes of emulsion 12 should likewise increase.Suitable pitches between adjacent beads of emulsion range from 0.030 to1.500 inches, and preferably from 0.175 to 0.375 inches.

If the emulsion 12 is to be directly exposed to the surface, i.e.,disposed on the outside of the substrate 10 as the wipe 8 is presentedto the user, the emulsion 12 preferably comprises a level at least 25percent, more preferably at least 50 percent, and most preferably atleast 75 percent of that of the basis weight of the substrate 10.Alternatively, if the emulsion 12 is disposed between two-plies ofsubstrate 10 in a laminate construction, for tissue applications,preferably the emulsion 12 comprises at least 150 percent, morepreferably at least 200 percent, and most preferably at least 250percent of the combined basis weight of the two plies. In such alaminate construction for hard surface cleaning applications, preferablythe emulsion 12 comprises at least 500 percent, more preferably at least650 percent, and most preferably at least 800 percent of the combinedbasis weight of the two plies.

It is to be noted that the basis weights described herein refer to theoverall basis weight of the substrate 10, as an average of the variousdifferent basis weight regions contained within the substrate 10. Thebasis weight of the substrate 10 may be measured according to ASTM TestMethod D3776-9, which test method is incorporated herein by reference,with results reported in pounds per 3,000 square feet. The emulsion 12weight is gravimetrically measured once the basis weight of thesubstrate 10 is known, as the tare.

If desired, the regions 14 of the substrate 10 free of the emulsion 12may be slightly wider in the cross machine direction at the edges of thewipe 8 than the corresponding regions 14 disposed at the interior of thewipe 8. This arrangement accommodates processing and slitting of a wide,multi-roll position web of the wipe 8 into narrower discrete units fortransport and sale to the consumer. It will be apparent to one skilledin the art that the regions 14 free of the substrate may form a borderat the other edges of the wipe 8 as well. Such a geometry can easily beaccomplished by not applying the emulsion 12 continuously. Instead, theemulsion 12 may be intermittently applied in the machine direction. Thesubstrate 10 is then cut or perforated in the cross machine directioncoincident the regions 14 free of the emulsion 12 in order to yielddiscrete or separable wipes 8.

Referring to FIG. 2, the emulsion 12 may define decorative indicia suchas macropatterns. The macropatterns may be used above, as shown, or maybe superimposed on the discontinuous stripe pattern of emulsion 12.Macropatterns of emulsion 12 provide the advantage that locally heavierloadings of water can be applied from a pattern that provides anaethetically pleasing visual cue to the user of where the emulsion 12 ispresent. Macropatterns of emulsion 12 may form decorative indicia. Suchdecorative indicia may be provided in the form of flowers, butterflies,clouds, tradenames, advertising, or any other planar pattern envisionedby the user.

In a preferred embodiment, the substrate 10 comprises a multi-basisweight tissue. A multi-basis weight substrate 10 may be made accordingto the aforementioned patents describing the same and incorporated byreference hereinabove. A multi-basis weight substrate 10 provides theadvantage that excess water will more easily saturate the low basisweight regions and, therefore, be more readily applied to the surface.Preferably the multi-basis weight substrate 10 comprises an essentiallycontinuous high basis weight network region with discrete low basisweight regions distributed throughout the essentially continuousnetwork.

Alternatively, a substrate 10 having a semi-continuous pattern of highand low basis weight regions may be selected. In yet a less preferredembodiment, a substrate 10 having an essentially continuous network oflow basis weight regions with discrete high basis weight regionsdistributed therein may be utilized, provided, however, one is willingto accept the strength tradeoff inherent in such a substrate 10. Such asubstrate 10, prophetically, provides the benefit that the essentiallycontinuous pattern of low basis weight regions will more readily allowwater expressed from the emulsion 12 to penetrate the substrate 10 andbe transferred to the surface.

If a substrate 10 having an essentially continuous high basis weightregion is selected, preferably the pitch of the discrete low basisweight regions is less than the pitch between adjacent stripes of theemulsion 12. This relative difference in pitches assures that theemulsion 12 will intercept the low basis weight regions and be morereadily transmitted therethrough, as described above.

For the embodiments described herein for tissue applications, asubstrate 10 having a basis weight of 7 to 10 pounds per 3,000 squarefeet per ply and 50 to 300, and more preferably 100 to 200 discrete lowbasis weight regions per square inch is suitable. For hard surfacecleaning applications, a substrate 10 having a basis weight of 20 poundsper 3,000 square feet and 100 to 200 discrete low basis weight regionsper square inch is suitable.

In a preferred embodiment, the wipe 8 may be made according to commonlyassigned U.S. Application entitled “Cleaning Articles Comprising aCellulosic Fibrous Structure Having Discrete Basis Weight RegionsTreated with A High Internal Phase Inverse Emulsion” filed Jul. 1, 1997,in the names of Nicholas J. Nissing et al., U.S. patent application Ser.No. 08/886,764, pending, the disclosure of which patent is incorporatedherein by reference.

If a substrate 10 having a semi-continuous basis weight pattern isselected, such a substrate 10 may be made according to commonly assignedU.S. Pat. No. 5,628,876, issued May 13, 1997 to Ayers et al., andincorporated herein by reference. Preferably, the semi-continuouspattern is oriented in the machine direction. If such a geometry isselected, prophetically, the beads of emulsion 12 may be applied to thesemi-continuous patterned substrate 10 such that the emulsion 12 isjuxtaposed with, and preferably coincident, the low basis weight regionsof the substrate 10. This arrangement provides the advantage, discussedabove, that the water expressed from the emulsion 12 is more readilytransmitted through the low basis weight regions of the semi-continuouspatterned substrate 10. The low basis weight regions of thesemi-continuous pattern, if parallel to the machine direction, may bedisposed on a pitch less than or equal to the stripes of the emulsion12.

It will be apparent to one skilled in the art that many variations arefeasible and within the scope of the claimed invention. For example, alaminate construction comprising emulsion 12 disposed between two pliesof substrate 10 may be made as described above. It is not necessary,however, that the plies be identical. One ply may be a nonwoven forstrength. The other ply may be a tissue to provide for transmission ofthe water to the surface. If desired, the nonwoven ply may be treated torender it hydrophobic and thereby ensure that the water released fromthe emulsion 12 is transferred to the surface via the tissue ply.

Alternatively, a laminate comprising two tissue plies may be selected.One of the plies may have a multi-basis weight region pattern describedabove. The multi-basis weight region may comprise a semi-continuouspattern. The other ply may comprise a single basis weight region forstrength. This embodiment provides for greater transmission of waterthrough one of the plies than through the other ply. Alternatively, themulti-basis weight region ply may comprise an essentially continuousnetwork of high basis weight regions with discrete low basis weightregions distributed therein.

In yet another embodiment, a laminate having a plurality of severallaminae may be provided. The laminae may comprise alternating plies ofsubstrate 10 and emulsion 12. Such a laminate may have two outwardlyfacing substrate 10 laminae as described above. The emulsion 12 may bewholly contained within the laminate. Alternatively, emulsion 12 may bedisposed on one exposed surface of such a laminate.

Referring to FIG. 3, in yet another embodiment stripes of emulsion 12may be comprised of discrete spheres of emulsion 12. The discretespheres of emulsion 12 are juxtaposed to collectively form thediscontinuous pattern. This arrangement provides the advantage of asuitable surface area to volume ratio, similar to the generallycylindrically shaped beads described above. Although stripes areillustrated in FIG. 3, one of ordinary skill will understand thatdiscrete spheres of emulsion 12 may be juxtaposed to form anydiscontinuous pattern desired.

Yet another variation, illustrated by FIG. 3 but applicable to any ofthe foregoing embodiments, is to vary the amount of the emulsion 12within the discontinuous pattern. For example, certain stripes ofemulsion 12 may have relatively more emulsion 12 than other stripes.This arrangement allows for locally heavier loading of the water ontothe surface to be cleaned, but yet still provides relatively drier edgesto minimize the amount of residual water left on the surface.

It will be apparent that, depending upon the desired application, thewipes 8 may be provided as discrete units, may be joined in seiatum byperforations, etc. The wipes 8 may be individually dispensed, such as iscommonly done for facial tissues. If individual dispensing is desired,the wipes may be provided in either a reach-in or pop up dispenser, asdisclosed in commonly assigned U.S. Pat. No. 4,623,074 issued Nov. 8,1986 to Dearwester; U.S. Pat. No. 5,520,308 issued May 28, 1996 to Berg.Jr. et al. and U.S. Pat. No. 5,516,001 issued May 14, 1996 to Muckenfuhset al., the disclosures of which are incorporated herein by reference.Alternatively, the wipes 8 may be core-wound, as disclosed in commonlyassigned U.S. Pat. No. 5,318,235, issued Jun. 7, 1994 to Sato, thedisclosure of which is incorporated herein by reference. If desired, thewipes 8 may be lightly compressed for packaging, provided care is takennot to rupture the emulsion 12. Such packaging may be accomplished asdisclosed in commonly assigned U.S. Pat. No. 5,664,897, issued Jul. 8,1997 to Young et al., the disclosure of which is incorporated herein byreference.

What is claimed is:
 1. A wipe comprising a laminate having a pluralityof laminae, said laminae comprising two outer plies and a central plydisposed therebetween, each of said outer plies comprising a substrate,said central ply being disposed on at least one of said outer plies,said central ply comprising a high internal phase inverse emulsiondisposed in a pattern comprising discrete macro-patterns or discretestripes, said outer plies having a combined first basis weight, saidemulsion having a coating weight, said coating weight being at least 150percent of said combined basis weight of said outer plies, said emulsionfurther having a surface area to volume ratio of less than 200 inches⁻¹.2. A wipe according to claim 1 wherein said coating weight of saidemulsion is at least 200 percent of said combined basis weight of saidouter plies.
 3. A process for making a wipe, said process comprising thesteps of: providing a substrate; providing a high internal phase inverseemulsion; disposing said emulsion on said substrate in a pattern wherebya first plurality of regions of said substrate is coated with saidemulsion, said emulsion comprising a plurality of sinusoidally shapedstripes and a second plurality of regions of said substrate is free ofsaid emulsion.
 4. A process according to claim 3 wherein said step ofdisposing said emulsion on said substrate comprises: moving one of saidsubstrate and said emulsion relative to the other in a machinedirection; and extruding said emulsion onto said substrate in aplurality of stripes, said stripes being generally parallel said machinedirection.
 5. A process according to claim 4 wherein said emulsion has asurface area to volume ratio greater than 50 inches⁻¹.
 6. A processaccording to claim 4 wherein said emulsion covers from 10 to 25 percentof the surface area of said substrate.
 7. A wipe comprising two outerplies, each of said outer plies comprising a substrate, said wipefurther comprising a high internal phase inverse emulsion disposedbetween said outer plies, wherein said emulsion is disposed in aplurality of sinusoidal stripes.
 8. A wipe according to claim 7 whereinsaid emulsion is disposed in a plurality of parallel stripes.
 9. A wipeaccording to claim 8 wherein said emulsion has a surface area to volumeratio less than or equal to 4/unit length.
 10. A wipe according to claim8 wherein at least one said ply comprises cellulose.
 11. A wipeaccording to claim 10 wherein both said plies comprise cellulose.